Mark Zuckerberg and Priscilla Chan have announced the birth of their second baby girl, August.
The two commemorated the joyous moment with a joint open letter that they posted on Facebook about childhood and innocence.
“When your sister was born, we wrote a letter about the world we hoped she and now you will grow up in ― a world with better education, fewer diseases, stronger communities, and greater equality,” the message read on Monday 28 August.
“We wrote that with all the advances in science and technology, your generation should live dramatically better lives than ours, and we have a responsibility to do our part to make that happen. Even though headlines often focus on what’s wrong, we still believe these positive trends will win out. We’re optimists about your generation and the future.”
The couple announced they were expecting a little sister for one-year-old daughter Max in March 2017 with a Facebook post that also addressed their struggle with infertility.
In their most recent post, the parents added that they hope August will be able to enjoy her youth while she is young.
“Childhood is magical,” they wrote. “You only get to be a child once, so don’t spend it worrying too much about the future.
“You’ve got us for that, and we’ll do everything we possibly can to make sure the world is a better place for you and all children in your generation.”
This story was originally published on the US version of HuffPost.